[PATCH] Extend next_timer_interrupt() to use a reference jiffie

For CONFIG_NO_HZ we need to calculate the next timer wheel event based on a
given jiffie value.  Extend the existing code to allow the extra 'now'
argument.  Provide a compability function for the existing implementations to
call the function with now == jiffies.  (This also solves the racyness of the
original code vs.  jiffies changing during the iteration.)

No functional changes to existing users of this infrastructure.

[ remove WARN_ON() that triggered on s390, by Carsten Otte <[email protected]> ]
[ made new helper static, Adrian Bunk <[email protected]> ]
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: john stultz <[email protected]>
Cc: Roman Zippel <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Thomas Gleixner authored and Linus Torvalds committed 2007-02-16 08:13:58 -08:00
1 parent 1cfd68496e
commit fd064b9b77
3 files changed
+22 -4

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@@ -61,7 +61,17 @@ extern int del_timer(struct timer_list * timer);
extern int __mod_timer(struct timer_list *timer, unsigned long expires);
extern int mod_timer(struct timer_list *timer, unsigned long expires);
/*
* Return when the next timer-wheel timeout occurs (in absolute jiffies),
* locks the timer base:
*/
extern unsigned long next_timer_interrupt(void);
/*
* Return when the next timer-wheel timeout occurs (in absolute jiffies),
* locks the timer base and does the comparison against the given
* jiffie.
*/
extern unsigned long get_next_timer_interrupt(unsigned long now);
/**
* add_timer - start a timer